The names of Chandragupta and his two successors in the Mauryan period are well known now. But reconstructing their lives and careers was a laborious and difficult process for the earlier historians.  

• There are hardly any comprehensive contemporary accounts or literary works which refer to the Mauryan emperors though they are mentioned in various Buddhist and Jain texts as well as in some Hindu works like the brahmanas.  
• The Mahavamsa, the comprehensive historical chronicle in Pali from Sri Lanka, is an important additional source.  
• The scattered information from these sources has been corroborated by accounts of Greek historians who left their accounts about India following Alexander’s campaign in north-western part of the country.  

Source: Tamil Nadu state board